I. Magnano

Longitudinal study of cognitive dysfunction in multiple sclerosis: neuropsychological, neuroradiological, and neurophysiological findings.

Objective: (1) To assess cognitive function and cerebral magnetic resonance imaging (MRI) involvement in relapsing-remitting multiple sclerosis; (2) to monitor disease evolution, cognitive dysfunction, and cerebral lesion burden over time (mean 8.5 year follow up period); (3) to study the relation between clinical, neuropsychological, and MRI data. On follow up assessment, visual and auditory oddball event related potentials (ERPs) were recorded as psychophysiological evaluation of cognitive status. Correlations between neuropsychological, MRI, and ERP data were also analysed. Methods: Neuropsychological study assessed verbal and non-verbal IQ, deterioration index (DI) from WAIS subtests, conceptual reasoning, attention, verbal and visuospatial short-term and long term memory. MRI assessment detected presence of demyelinating lesions by using a semiquantitative method as well as cortical and subcortical atrophy over time. Results: Attention, short-term and long term visuospatial memory were mildly impaired at baseline and remained unaltered longitudinally. At retesting a significant worsening of verbal long term memory (p=0.023), DI presence (p=0.041) and the increase of supratentorial and subtentorial MRI lesions load (p=0.001) emerged. Expanded disability status scale score correlated significantly with total lesion burden at both evaluations (p=0.043 and p=0.024 respectively). Temporal, occipital, and frontal horn lesions as well as cortical atrophy correlated significantly with attention and memory tests at baseline. Follow up assessment revealed significant correlation between cortical atrophy and attention as well as visuospatial short-term memory; spatial long term memory correlated significantly with lesions in body of lateral ventricle and frontal lobe. ERP study showed P300 latency abnormalities in 75% of patients, involving specifically more visual P300 (58.4 % of cases) than auditory wave (41.6 %). Visual P300 latency and amplitude correlated significantly with DI and auditory P300 latency with frontal horn and brain stem lesions. Conclusions: These findings revealed mild cognitive impairment in MS patients particularly consistent with slowing information processing over time. Increased MRI lesions do not correlate with the clinical course of the disease and cognitive deficit evolution. Thus, cognitive dysfunction could be related to disease peculiarity and not to the time course. Correlations between P300, neuropsychological, and MRI findings provide further information about ERP application to examine cognitive impairment in MS and probably to investigate their neural origin.

Visual and auditory event-related potentials in sporadic amyotrophic lateral sclerosis

OBJECTIVES To investigate the relationship between amyotrophic lateral sclerosis (ALS) and cognitive function by means of oddball event-related potentials (ERPs) and to determine the usefulness of this methodology in the cognitive status assessment of physically disabled patients. METHODS Visual and auditory oddball ERPs were recorded in 16 consecutive sporadic ALS patients. A comprehensive battery of neuropsychological (NP) tests assessed intelligence, executive functions, attention, memory, word fluency, visuo-motor and visual-constructive skills. RESULTS All patients performed visual and auditory ERPs and 75% of cases showed abnormal N200 and/or P300 waves. Ten patients (62.5%) carried out the entire psychometric evaluation with significant impairment on tests of executive function and attention. A significant correlation between delayed visual (P<0.04) and auditory (P<0.04) P300 latency and impaired NP tests was found. CONCLUSIONS In agreement with literature data, our findings confirm the hypothesis of cognitive impairment in ALS patients especially on attention and executive functions suggesting a more extensive degeneration beyond the motor areas. ALS causes severe physical disabilities and such a condition may interfere with NP testing. Thus, the P300 seems to be a useful tool for the assessment of cognition and attention when severe physical deficits are present.

Pure post-stroke cerebellar cognitive affective syndrome: a case report.

Abstract.Cerebellar pathology commonly shows important motor signs and less evident cognitive dysfunction. The ’cerebellar cognitive affective syndrome’ is characterised by impairment on executive function, spatial cognition, language and behaviour. We report the case of a man with acute onset of transitory motor features and severe mental disorders. Cranial CT and brain MRI revealed extended cerebellar lesions. Neuropsychological assessment disclosed deficits of attention, executive function and memory. Auditory event–related potentials showed abnormal P300. These data suggest a pure “cerebellar cognitive affective syndrome” and strengthen the hypothesis of cerebellar cognitive function modulation.

Cognitive impairment and neurophysiological correlates in MS

Cognitive impairment in multiple sclerosis (MS) has received considerable interest over the last decades. Heterogeneous patterns of cognitive dysfunction have been reported in literature in relation to the subtype of the disease and the severity of specific cognitive domains affected. Event related potentials (ERPs), especially P300, have been employed to evaluate the cognitive decline in MS and neurophysiological findings agree with data obtained by neuropsychological testing. The objectivity, the reliability and the easy administration are the main features of ERP technique but more specific attention and memory tasks are needed to enhance the clinical value of the methodology. Moreover, ERP recording has the advantage of being feasible even in severe disabled patients. Finally, longitudinal ERP studies are required to investigate the natural course of cognitive dysfunction in MS, to estimate the prognostic value of subclinical defects in different clinical form of the disease and to evaluate clinical benefits of therapeutic and rehabilitative interventions.

Exploring brainstem function in multiple sclerosis by combining brainstem reflexes, evoked potentials, clinical and MRI investigations

OBJECTIVE To investigate vestibulo-masseteric (VMR), acoustic-masseteric (AMR), vestibulo-collic (VCR) and trigemino-collic (TCR) reflexes in patients with multiple sclerosis (MS); to relate abnormalities of brainstem reflexes (BSRs) to multimodal evoked potentials (EPs), clinical and Magnetic Resonance Imaging (MRI) findings. METHODS Click-evoked VMR, AMR and VCR were recorded from active masseter and sternocleidomastoid muscles, respectively; TCR was recorded from active sternocleidomastoid muscles, following electrical stimulation of the infraorbital nerve. EPs and MRI were performed with standard techniques. RESULTS Frequencies of abnormal BSRs were: VMR 62.1%, AMR 55.1%, VCR 25.9%, TCR 58.6%. Brainstem dysfunction was identified by these tests, combined into a four-reflex battery, in 86.9% of cases, by EPs in 82.7%, MRI in 71.7% and clinical examination in 37.7% of cases. The sensitivity of paired BSRs/EPs (93.3%) was significantly higher than combined MRI/clinical testing (70%) in patients with disease duration ⩽6.4years. BSR alterations significantly correlated with clinical, EP and MRI findings. CONCLUSIONS The four-BSR battery effectively increases the performance of standard EPs in early detection of brainstem impairment, otherwise undetected by clinical examination and neuroimaging. SIGNIFICANCE Multiple BSR assessment usefully supplements conventional testing and monitoring of brainstem function in MS, especially in newly diagnosed patients.

P300 and executive function alterations: possible links in a case of Morgagni-Stewart-Morel syndrome

To evaluate possible cause-effect relationships between hyperostosis frontalis interna and cognitive dysfunction, we performed a neurophysiological (event-related potentials, ERPs) and neuropsychological study in a case of Morgagni-Stewart-Morel (MSM) syndrome associated with frontal lobe compression. Neuropsychological evaluation evidenced selective impairment of executive function. Visual and auditory oddball ERPs revealed delayed P300 latency and reduced auditory P300 amplitude with multi-peaked morphology. ERP abnormalities and cognitive dysfunction could be due to the frontal bone-cortex conflict documented by neuroradiological investigations.

Neuropsychophysiological findings in a case of long-standing overt ventriculomegaly (LOVA).

Long-standing overt ventriculomegaly in adults (LOVA) is a clinical entity characterized by chronic hydrocephalus with infant onset, slow evolution and clinical disturbances during adulthood. Few cases are reported in literature describing the evident contrast between the severity of hydrocephalus and the relatively spared neurological functioning and cognitive aspects. The authors describe a 59-year-old man with congenital hydrocephalus complaining of persistent gait impairment. Neurological examination showed a mild paraparesis, severe higher cortical function impairment but relatively sparing of daily living activity. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a very remarkable ventriculomegaly compressing the brain cortex but sparing the cerebellum and the brainstem. Brain Single Photon Emission Computer Tomography (SPECT) showed a prevalent cerebellar perfusion as well. Neuropsychological testing was consistent with severe cognitive deterioration and attention disorders. Language and praxis functions seemed to be preserved. Auditory oddball ERPs (P300) showed morphological abnormalities especially of late components. This case report demonstrates in vivo the level of adaptation to which human brain can reach under chronic mechanic stress conditions. The striking poor cerebral parenchyma representation and the relatively spared language and praxic abilities account for a functional reorganization of residual structures due to the neural plasticity.

VEMPs in central neurological disorders

http://dx.doi.org/10.1016/j.clinph.2016.01.02

W7.4 Linguistic event related potential (ERP) study in mild cognitive impairment (MCI)

decision-making tool to neonatologists when a neonatal neurophysiologist is not available. Objectives: To compare c-EEG and a-EEG classifications for HIE in order to assess and avoid pitfalls in decision-making process. Methods: Twenty HIE full-term infants’ early EEG recordings (8-channel c-EEG with simultaneous C3-C4 a-EEG reconstruction) are comparatively analyzed according c-EEG and a-EEG classifications. Results: The a-EEG upper margin reliability is bad, so a-EEG frequently underestimates the severity of c-EEG depression. Inversely, the a-EEG lower margin specificity is good, avoiding wrong hypothermia decisions, except when subcontinuous status of low voltage is disturbing this lower margin. Conclusions: Thus, a-EEG remains a rough but useful emergency decisionmaking tool, whose lower margin specificity remains good, and sensitivity upgraded if registered early during the free-of-seizure first hours of life. Simultaneous multichannel c-EEG and a-EEG recordings would be the best in order to avoid artifacts or seizures pitfalls.